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Abstract:

A system for the thermal conditioning of a fluid, more particularly of a
drilling mud, in preparation for subsequent cycles of analysis of the
composition of said fluid is disclosed, wherein the system provides for
the presence of at least one generator of microwaves for the heating of
said fluid and a cylinder of non-stick material wherein said fluid flows;
said system and method being such that the heating of said mud takes
place in less than 70 seconds.

Claims:

1. A system for the thermal conditioning of a fluid, more particularly of
a drilling mud, in preparation for subsequent cycles of analysis of the
composition of said fluid, wherein it comprises at least one generator of
microwaves for the heating of said fluid and a cylinder wherein said
fluid flows.

2. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to claim 1, wherein said cylinder is made up
of non-stick material with features adequate for the specific work
conditions in such a way as to avoid the formation of solid residues or
incrustation of said fluid within the path traversed.

3. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to the previous claims, wherein said
generator of microwaves is connected to said cylinder in such a way as to
heat the fluid contained inside said cylinder.

4. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to the previous claims, wherein the heating
of the mud takes place in less than 70 seconds.

5. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to the previous claims, wherein saia
generators of microwaves are placed inside over-pressurised containers
suitable for functioning in an explosive area.

6. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to claims 1, 2, 3 and 4, wherein said
generators of microwaves are made safe for functioning in an explosive
area by means of the "intrinsic safety" method.

7. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to claims, 1, 2 and 3 and 4, wherein said
generators of microwaves are made safe for the functioning in an
explosive area by means of the "anti-deflagration" method.

8. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to claims 1, 2, 3, 4 and 5 or 1, 2, 3, 4 and
6 or 1, 2, 3, 4 and 7, wherein it comprises a circuit for cooling
preferably with water.

9. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to claims 1, 2, 3, 4 and 5 or 1, 2, 3, 4 and
6 or 1, 2, 3, 4 and 7, wherein it comprises a circuit for cooling
preferably with air.

10. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to claims 1, 2, 3, 4, 5 and 8 or 1, 2, 3, 4,
6 and 8 011, 2, 3, 4, 7 and 8 or 1, 2, 3, 4, 5 and 9 or 1, 2, 3, 4, 6 and
9 or 1, 2, 3, 4, 7 and 9, wherein the fluid at output from said system is
subjected to degassing and the gases extracted are subjected to a
subsequent composition analysis.

11. The system for the thermal conditioning of a fluid, more particularly
of a drilling mud, according to claims 1, 2, 3, 4, 5, 8 10 or 1, 2, 3, 4,
6, 8 and 10 or 1, 2, 3, 4, 7, 8 and 10 or 1, 2, 3, 4, 5, 9 and 10 or 1,
2, 3, 4, 6, 9 and 10 or 1, 2, 3, 4, 7, 9 and 10, wherein it comprises two
devices for the measurement of the temperature of said fluid: one for
measuring the temperature at input in said system and one for measuring
the temperature at output in said system.

12. A method for the thermal conditioning of a fluid, more particularly
of a drilling mud, wherein it comprises the following phases: measurement
of the temperature of the mud at output from the drilling probe, before
entrance in the system of thermal conditioning; heating of the mud by
means of the application of microwaves to the fluxing pipe wherein said
mud flows measurement of the temperature at output from the system of
heating of the mud; possible degassing of the mud and extraction of
gaseous hydrocarbons contained in said mud; quantitative and qualitative
analysis of the hydrocarbons extracted.

Description:

CROSS-REFERENCE TO RELATED APPPLICATION

[0001] This application claims the benefit of the priority filing date of
Italian patent no. MI2010A001324 filed on Jul. 19, 2010 in the name of
GEOLOG S.p.A.

FEDERALLY SPONSORED RESEARCH

[0002] Not Applicable

SEQUENCE LISTING OR PROGRAM

[0003] Not Applicable

STATEMENT REGARDING COPYRIGHTED MATERIAL

[0004] Portions of the disclosure of this patent document contain material
that is subject to copyright protection. The copyright owner has no
objection to the facsimile reproduction by anyone of the patent document
or the patent disclosure as it appears in the Patent and Trademark Office
file or records, but otherwise reserves all copyright rights whatsoever.

BACKGROUND

[0005] The present invention relates to a system and a method of thermal
conditioning as a continuous process of a fluid sample, more particularly
of an oil drilling mud

[0006] During the drilling of an oil well, a fluid known as drilling mud
is made to circulate inside the hole while drilling. The drilling mud has
various functions including, in particular, those of: supporting the
drilled hole, lubricating and cooling the auger while drilling of the
well. The drilling mud has, moreover, the function of conveying rock
fragments to the surface produced while drilling. The rock fragments are
produced by the mechanical impact of the drill bit traversing the rocky
layer, resulting in drilling debris and volatile substances released
during the break-up action.

[0007] Among fluids and gaseous components, liquid and gaseous
hydrocarbons are of particular importance because they are indicators of
the existence of an oil or gas deposit.

[0008] The gaseous fraction contained in the drilling mud conveyed to the
surface is commonly extracted by means of an apparatus known as degasser,
after which it is diluted in a carrier gas, generally air, and finally
transferred to various analysis apparatuses able to identify the quality
and quantity of various components of hydrocarbons present. The degasser
is continuously fed by a volumetric pump which samples the fluid to be
degassed at the point closest to the well exit.

[0009] In certain working conditions, in particular in the drilling of
wells in deep waters (from 1000 to 3000 metres of water), the drilling
mud must upwardly traverse a column of water of considerable height,
cooling progressively, before reaching the point of sampling. Due to this
cooling, the drilling mud that reaches the degasser has a temperature
often below 10° C. Such a temperature entails considerable
difficulties in extracting and analyzing the hydrocarbons present.

[0010] Also, in these conditions, the rise of mud is at times aided by a
supplementary pump that injects drilling mud already degassed into a
circuit rising from the seabed, in this way diluting the mud coming from
the well and consequently the gaseous fraction contained therein. This
considerably reduces the percentage of hydrocarbons present in unit of
volume, making their extraction and quantification additionally
difficult.

[0011] For these reasons, the hydrocarbons brought to the surface may be
in extremely low concentrations (and in two-phase gas/liquid
equilibrium), conditions which as a whole make the subsequent process of
extraction and analysis in gaseous phase very difficult.

[0012] It is therefore necessary to thermally, i.e. heat, condition the
drilling mud so as to facilitate the extraction of the hydrocarbons
thereby improving the precision and resolution of their subsequent
analysis.

[0013] The systems for thermal conditioning of drilling mud currently
present on the market are essentially electric heating systems that use
plate heat exchangers. These systems, however, have various
disadvantages, including the length of time interval required for raising
the temperature of the drilling mud, which consequently delays the
sending of the gas sample for subsequent qualitative and quantitative
hydrocarbon analysis. This delay may be particularly hazardous in light
of the particular risks involved in handling certain gases.

SUMMARY OF THE INVENTION

[0014] The object of the present invention is that of providing a system
of thermal conditioning of a fluid, in particular, oil drilling mud,
which allows its temperature to be quickly raised beyond the volatility
limit of its components to be analysed. In particular, while known
systems of heating take up to 15 minutes to bring the temperature to a
sufficient value (approximately 80° C.) for the complete
extraction of hydrocarbons, the present system achieves the same
objective in less than 70 seconds.

[0015] This object is achieved by a system of heating based on microwaves
which achieves rapid rising of temperatures. This feature permits the
sample of heated mud to reach the subsequent stage of extraction and
analysis considerably earlier compared to known systems, and to give
advance notice of possible dangers connected to the presence of gas. This
allows for more time to adopt measures to safeguard persons, the
environment, and equipment.

[0016] Secondly, yet equally importantly, this feature of reducing
heating/transit times provides a more representative sample and a better
analytical resolution of the various components in the subsequent phase
of analysis.

[0017] Another considerable disadvantage of known systems of heating comes
from the formation of solid residues (incrustations) caused by heating
mud at high temperatures. These incrustations may cause blockages in the
labyrinth paths of plate exchangers, consequently interrupting the
process.

[0018] A second object of the present invention, therefore, is that of
providing a system of thermal conditioning of a drilling mud which does
not allow the formation and deposit of solid residues (incrustations)
produced by the heating of fluid. This object is achieved due to the
simultaneous presence of several elements: the elimination of typical
labyrinth paths of plate exchangers which, due to their actual
configuration, are subject to blockages; the use of microwaves which
allow rapid heating and which does not generate incrustations; and the
use of a pipe of non-stick material as a container in which to make the
mud flow adequate for specific working conditions.

[0019] Another typical problem of systems of thermal conditioning comes
from the formation and consequent accumulation of gaseous bubbles inside
a circuit. A third object of the present invention, therefore, is that of
completely eliminating the risk of separation and accumulation of gaseous
bubbles inside the circuit. This object is achieved by eliminating the
typical labyrinth paths of heat exchangers which, due to their geometric
configuration, often causes the formation of bubbles, and the use of a
rectilinear pipe of non-stick materia as container in which to make the
mud flow.

[0020] A final disadvantage which may be encountered with known systems
comes from the likelihood that blockages may occur due to a solid
component which is normally present in drilling mud. In known systems of
thermal conditioning, it is necessary to filter mud beforehand in order
to eliminate any solid component. The prior ultra-filtering of the mud
may also cause the elimination of a part of the gaseous component which
should instead be retained and analysed. Therefore, a further object of
the present invention is that of providing a system of thermal
conditioning of drilling mud which allows for the circulation of a fluid
also containing a solid component (which naturally must not have
excessive dimensions) in order to avoid prior ultra-filtering. This
object is also achieved by eliminating the labyrinth paths of plate
exchangers whose geometric features may cause the formation of blockages,
and the use of an adequate section a rectilinear pipe of non-stick
material as container in which to make the mud flow.

[0021] These and further features of the present invention will be made
clearer on reading the following detailed description of a preferred
embodiment of the present invention to be considered by way of a
non-limiting example of the more general concepts claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The following description refers to the accompanying drawings, in
which:

[0023]FIG. 1 is an exemplary diagram of the functioning of a system of
extraction, thermal conditioning and degassing of drilling mud,
considered as a whole.

[0024]FIG. 2 shows only the system of thermal conditioning of drilling
mud.

DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

[0025] Referring to FIG. 1, a system for the extraction, thermal
conditioning and degassing of drilling mud is made up of the following
main elements: [0026] a volumetric pump 1 [0027] a system of thermal
conditioning of the mud 2 [0028] a measurer 3 of the flow and temperature
at input in said conditioning system [0029] a pneumatic box 4 for
maintaining the system of thermal conditioning under safety conditions
[0030] a degasser 5 [0031] a measurer 6 of the temperature at output.

[0032] The functioning of the system made up of the elements described
above is described herein below. The drilling mud comes from the probe
via the line 7 arrives at the volumetric pump 3. The latter pushes the
mud towards the box which encloses the system of thermal conditioning 2.
On the line 8, along which flows the mud which arrives at the box of the
system of thermal conditioning, a measurer 3 of flow and temperature is
placed. The value of temperature and flow at input in the system of
thermal conditioning measured by the device 3 is sent to the electronic
block 9 placed in a cabin in a safe area.

[0033] During the traversing of the box of thermal conditioning, the
drilling mud is heated, raising the temperature to a sufficient value
(approximately 80° C.) for the complete extraction of the
hydrocarbons present, in a time less than 70 seconds. After heating, the
temperature of the mud is once again measured by means of the measurer of
the temperature at output 6. The value of the temperature at output
measured by 6 is sent to the electronic block placed in the cabin where
the measurement of the temperature at input also arrives, so as to
monitor the heating procedure. The temperature values, measured and
acquired by the control unit placed inside the control cabin situated in
a safe area, are used to pilot the modules of heating with microwaves in
order to maintain a constant temperature which is adequate for the
purpose. The mud at output from the box of thermal conditioning arrives
at the degasser 5. Said degasser 5 is made up of a cylindncal container
provided below with an input mouth 10 and laterally with a discharge
mouth 11 for the drilling mud.

[0034] Inside the cylindrical container there is a mechanical stirrer 12
actuated by an electric motor 13 to create a centrifugal movement of the
mud which encourages the separation upwards of the gaseous fraction.

[0035] The gas which is separated at the head of the cylindrical container
is conveyed by means of a vacuum line 14 to the apparatuses for the
qualitative and quantitative analysis of the gas sample.

[0036] Referring to FIGS. 1 and 2, the system of thermal conditioning 2
according to the present invention is made up of: [0037] a first
generator of microwaves 15 [0038] a second generator of microwaves 15'
[0039] a fluxing cylinder 16 in non-stick material with features that are
adequate for the specific working conditions [0040] a container 17 of the
fluxing cylinder in Teflon.

[0041] The drilling mud enters the interior of the system of heating by
means of the input mouth 18 and traverses the fluxing cylinder 16. During
the traversing of the fluxing cylinder 16, the mud is heated by
microwaves produced by the two generators 15 and 15'. The generators of
microwaves are connected by means of the lines 19 and 20, 19' and 20' to
the pneumatic box of pressurisation 4 and are provided with safety valves
21 and 21'. The maintaining of an overpressure inside the system also
allows the installation of the apparatus in areas considered potentially
hazardous (zone 1 and zone 2).

[0042] As an alternative to the system described above, it is possible to
use other solutions to allow the installation in hazardous areas. These
solutions are, for example, "intrinsic safety" and "anti-deflagration"

[0043] Said generators of microwaves 15 and 15' are connected via the two
supply lines 22 and 22' to the control unit placed inside the control
cabin situated in a safe area.

[0044] The fluxing cylinder is a pipe preferably in non-stick material
with features notoriously adequate for the specific working conditions,
able to prevent the formation of solid residues or incrustations. At the
output from the fluxing cylinder, the mud arrives at the cylindrical
container of the degasser where mechanical stirring takes place for the
separation of the gaseous hydrocarbons.

[0045] The generators of microwaves 15 and 15' are provided with two
cooling circuits 23 and 23' preferably with water or with air. A system
is thus made for the heating of the drilling mud, able to quickly heat
said mud so as to make the entire procedure of detecting the presence of
gaseous hydrocarbons faster.

[0046] From the description given above, it is possible to note the total
lack of the typical labyrinth paths of heat exchangers. In the present
invention, in fact, during the operation of heating, the mud only passes
through a fluxing cylinder of non-stick material. The simple geometry of
such a path and the features of anti-adherence of the material whereof
said path is constituted, combined with the use itself of the microwaves,
results in a device capable of overcoming all the limitations of known
thermal conditioning devices in an efficient manner.

Patent applications by Antonio Calleri, Milano IT

Patent applications in class WITH HEATING OR COOLING (1) WITHIN THE BORE, OR (2) DRILLING FLUID

Patent applications in all subclasses WITH HEATING OR COOLING (1) WITHIN THE BORE, OR (2) DRILLING FLUID